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-   -   Convection–diffusion equation solver (http://www.cfd-online.com/Forums/openfoam-solving/82381-convection-diffusion-equation-solver.html)

 Daniele111 November 24, 2010 16:24

Convection–diffusion equation solver

Hi
I would create my solver for convectio-diffusion equation:

http://upload.wikimedia.org/math/5/4...779b9a954a.pngWhere v field is know. Where should I star to solve this problem? How can I create OpenFoam code? I would use simpleFoam to calculate U field and join simpleFoam solver with my solver to have only one solver to calculate scalar field c.
Thanks

 akidess November 25, 2010 05:25

Your problem is pretty much equivalent to this one: http://openfoamwiki.net/index.php/Ho...ure_to_icoFoam. Just instead of adding the equation to icoFoam, do so with simpleFoam.

 Daniele111 November 25, 2010 06:40

Thanks
Perfect, but in simpleFoam (or pisoFoam) where I add this line:

dimensionedScalar nu ( transportProperties.lookup("nu") );

for my scalar transport properties?

 akidess November 25, 2010 09:54

I would add the following code to createFields.H:

Code:

```Info<< "Reading transportProperties\n" << endl; IOdictionary transportProperties (     IOobject     (         "transportProperties",         runTime.constant(),         mesh,         IOobject::MUST_READ,         IOobject::NO_WRITE     ) ); dimensionedScalar DC (     transportProperties.lookup("DC") ); Info<< "Reading field C\n" <<endl; volScalarField C (     IOobject     (         "C",         runTime.timeName(),         mesh,         IOobject::MUST_READ,         IOobject::AUTO_WRITE     ),     mesh );```

 Daniele111 November 25, 2010 10:04

Yes I just do it.
Then I would join electrostaticFoam with my_simpleFoam, so I'll modify createFieds.h and my_simpleFoam.c adding electrostaticFoam. It's correct?
But can I impose different boundary condition on the same patch? Example:
symmetryPlane for potential (for electric fields) and